The embargo dam began cracking earlier today with the premature release of the X6 ActiveHybrid's details, so BMW decided to open the floodgates and reveal all its Frankfurt-bound hybrids ahead of the show, beginning with the 2010 BMW ActiveHybrid 7.

The big sedan uses a different electric drive setup from the coupe-shaped 'ute: a mild hybrid co-developed with Mercedes-Benz that combined with an electric motor and a twin-turbo 4.4-liter V8, yields 455 hp and 516 lb-ft of torque. The V8 has been upgraded from the standard 400 to 440 hp (with the extra 15 hp coming from the electric motor), and unlike the two-mode hybrid system in the X6, this mild hybrid has the single motor sandwiched between the engine and the new ZF eight-speed automatic transmission.

Another difference from the X6 is the use of a 120V lithium ion battery pack rather the nickel metal hydride unit in the crossover. The hybrid drive should bump the fuel efficiency by about 15 percent overall, putting it at about 19-20 mpg combined while getting to 60 mph in about 4.8 seconds. The ActiveHybrid will be available in both standard and extra-long variants, and the production version of the ActiveHybrid 7 will debut at the Frankfurt Motor Show next month, with sales beginning later this year. Full press release below the fold.